Bunuel wrote:
Epidemiologist: Malaria passes into the human population when a mosquito carrying the virus bites a human who has no immunity. The malaria parasite can remain for up to forty days in the blood of an infected person. The disease cannot be passed from person to person, unless a non-infected person is exposed to the blood of an infected person. Theoretically, malaria could be eradicated in any given area, if all the mosquitoes carrying malaria in that area are exterminated. If such a course of action is carried out at a worldwide level, then the global eradication of malaria is possible.
Which of the following, if true, suggests that the epidemiologist’s plan for eliminating malaria is not viable?
A. A person who is infected with malaria can infect a mosquito that is not carrying malaria, if that mosquito bites such a person.
B. Unless a mosquito bites an infected person, and then bites a non-infected person, malaria cannot be passed directly from human to human.
C. Malaria is still endemic in many parts of the world, and many health workers believe that the global eradication of malaria is not possible.
D. Some people in areas where malaria is rife have developed an immunity to mosquitos, yet they are also show a higher incidence of genetic disorders such as sickle-cell anemia.
E. Mosquitos in many developing parts of the world are responsible for passing on a variety of viruses to human hosts.
MAGOOSH Official Explanation
The paragraph is essentially saying that if we kill every malarial mosquito, then once the last such mosquito is killed, we have effectively eradicated malaria.
(A) exposes the flaw in this plan. Since a person can carry malaria for up to 40 days, all they have to do is infect a non-malarial mosquito, and the whole process starts over again.
(B) just describes the typical transmission of malaria. It does not relate to the plan in the paragraph.
(C) is wrong. What health workers believe doesn’t directly affect the argument. It may suggest that the plan has doubters, but nothing more.
(D) brings in two irrelevant topics: immunity and sickle-cell anemia.
(E) just describes mosquito behavior in general and is not specific to the paragraph.